The invention described in this patent comprises a method of regulating when coal dust or liquid fuel is supplied by air or gas to the working cylinder.
The invention comprises a reservoir supplied by a pump with gas, air or a mixture of the two, and this air or gas is mixed with coal dust or liquid fuel through a valve such as that used in the former invention, and passes to the cylinder through a valve which remains open for a period determined by the governor.
The pressure in the reservoir must always exceed the greatest pressure in the cylinder, the amount of excess being determined by a relief valve, the load on which is controlled by the governor, or by springs, or by the supply pump. The reservoir may also be supplied with air compressed in the working cylinder during the return stroke of the piston, the air being admitted to the reservoir by the lifting of a suitable valve. Too great a compression pressure in the cylinder lifts this valve against the action of a spring .
The air from the reservoir and the gaseous or liquid fuel may be supplied to the cylinder by separate nozzles arranged either concentrically or side by side. To ensure a thorough mixture of the fuel and air in the cylinder the fuel may be supplied to a perforated tube or to a rose, or to mixing nozzles, or the distributor may be arranged so that the return stroke of the piston causes the air to pass over the distributor.
In another arrangement the fuel is supplied at the side, and ribs are employed to cause the air under compression to pass over the outlets, or plates are attached to the piston, or the nozzle may be arranged to travel backwards with the piston for the same purpose.
All the valves are actuated by cams which can be moved endwise means of a hand lever, so that the fuel admission valve is put out of gear, while compressed air from the reservoir is admitted through one valve and exhausted through another valve until the required speed has been reached, when the cams are again returned to the positions in which they actuate the valves in the normal way.